FD.io VPP  v18.04-17-g3a0d853
Vector Packet Processing
sysfs.c
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1 /*
2  * Copyright (c) 2017 Cisco and/or its affiliates.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at:
6  *
7  * http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 
16 #include <vppinfra/clib.h>
17 #include <vppinfra/clib_error.h>
18 #include <vppinfra/format.h>
19 
20 #include <sys/types.h>
21 #include <sys/stat.h>
22 #include <fcntl.h>
23 #include <dirent.h>
24 
26 clib_sysfs_write (char *file_name, char *fmt, ...)
27 {
28  u8 *s;
29  int fd;
30  clib_error_t *error = 0;
31 
32  fd = open (file_name, O_WRONLY);
33  if (fd < 0)
34  return clib_error_return_unix (0, "open `%s'", file_name);
35 
36  va_list va;
37  va_start (va, fmt);
38  s = va_format (0, fmt, &va);
39  va_end (va);
40 
41  if (write (fd, s, vec_len (s)) < 0)
42  error = clib_error_return_unix (0, "write `%s'", file_name);
43 
44  vec_free (s);
45  close (fd);
46  return error;
47 }
48 
50 clib_sysfs_read (char *file_name, char *fmt, ...)
51 {
52  unformat_input_t input;
53  u8 *s = 0;
54  int fd;
55  ssize_t sz;
56  uword result;
57 
58  fd = open (file_name, O_RDONLY);
59  if (fd < 0)
60  return clib_error_return_unix (0, "open `%s'", file_name);
61 
62  vec_validate (s, 4095);
63 
64  sz = read (fd, s, vec_len (s));
65  if (sz < 0)
66  {
67  close (fd);
68  vec_free (s);
69  return clib_error_return_unix (0, "read `%s'", file_name);
70  }
71 
72  _vec_len (s) = sz;
73  unformat_init_vector (&input, s);
74 
75  va_list va;
76  va_start (va, fmt);
77  result = va_unformat (&input, fmt, &va);
78  va_end (va);
79 
80  vec_free (s);
81  close (fd);
82 
83  if (result == 0)
84  return clib_error_return (0, "unformat error");
85 
86  return 0;
87 }
88 
89 u8 *
91 {
92  char *p, buffer[64];
94  u8 *s = 0;
95  int r;
96 
97  r = readlink (link, buffer, sizeof (buffer) - 1);
98 
99  if (r < 0)
100  return 0;
101 
102  buffer[r] = 0;
103  p = strrchr (buffer, '/');
104 
105  if (!p)
106  return 0;
107 
108  unformat_init_string (&in, p + 1, strlen (p + 1));
109  if (unformat (&in, "%s", &s) != 1)
110  clib_unix_warning ("no string?");
111  unformat_free (&in);
112 
113  return s;
114 }
115 
116 clib_error_t *
117 clib_sysfs_set_nr_hugepages (int numa_node, int page_size, int nr)
118 {
119  clib_error_t *error = 0;
120  struct stat sb;
121  u8 *p = 0;
122 
123  p = format (p, "/sys/devices/system/node/node%u%c", numa_node, 0);
124 
125  if (stat ((char *) p, &sb) == 0)
126  {
127  if (S_ISDIR (sb.st_mode) == 0)
128  {
129  error = clib_error_return (0, "'%s' is not directory", p);
130  goto done;
131  }
132  }
133  else if (numa_node == 0)
134  {
135  vec_reset_length (p);
136  p = format (p, "/sys/kernel/mm%c", 0);
137  if (stat ((char *) p, &sb) < 0 || S_ISDIR (sb.st_mode) == 0)
138  {
139  error = clib_error_return (0, "'%s' does not exist or it is not "
140  "directory", p);
141  goto done;
142  }
143  }
144  else
145  {
146  error = clib_error_return (0, "'%s' does not exist", p);
147  goto done;
148  }
149 
150  _vec_len (p) -= 1;
151  p = format (p, "/hugepages/hugepages-%ukB/nr_hugepages%c", page_size, 0);
152  clib_sysfs_write ((char *) p, "%d", nr);
153 
154 done:
155  vec_free (p);
156  return error;
157 }
158 
159 
160 static clib_error_t *
161 clib_sysfs_get_xxx_hugepages (char *type, int numa_node,
162  int page_size, int *val)
163 {
164  clib_error_t *error = 0;
165  struct stat sb;
166  u8 *p = 0;
167 
168  p = format (p, "/sys/devices/system/node/node%u%c", numa_node, 0);
169 
170  if (stat ((char *) p, &sb) == 0)
171  {
172  if (S_ISDIR (sb.st_mode) == 0)
173  {
174  error = clib_error_return (0, "'%s' is not directory", p);
175  goto done;
176  }
177  }
178  else if (numa_node == 0)
179  {
180  vec_reset_length (p);
181  p = format (p, "/sys/kernel/mm%c", 0);
182  if (stat ((char *) p, &sb) < 0 || S_ISDIR (sb.st_mode) == 0)
183  {
184  error = clib_error_return (0, "'%s' does not exist or it is not "
185  "directory", p);
186  goto done;
187  }
188  }
189  else
190  {
191  error = clib_error_return (0, "'%s' does not exist", p);
192  goto done;
193  }
194 
195  _vec_len (p) -= 1;
196  p = format (p, "/hugepages/hugepages-%ukB/%s_hugepages%c", page_size,
197  type, 0);
198  error = clib_sysfs_read ((char *) p, "%d", val);
199 
200 done:
201  vec_free (p);
202  return error;
203 }
204 
205 clib_error_t *
206 clib_sysfs_get_free_hugepages (int numa_node, int page_size, int *v)
207 {
208  return clib_sysfs_get_xxx_hugepages ("free", numa_node, page_size, v);
209 }
210 
211 clib_error_t *
212 clib_sysfs_get_nr_hugepages (int numa_node, int page_size, int *v)
213 {
214  return clib_sysfs_get_xxx_hugepages ("nr", numa_node, page_size, v);
215 }
216 
217 clib_error_t *
218 clib_sysfs_get_surplus_hugepages (int numa_node, int page_size, int *v)
219 {
220  return clib_sysfs_get_xxx_hugepages ("surplus", numa_node, page_size, v);
221 }
222 
223 clib_error_t *
224 clib_sysfs_prealloc_hugepages (int numa_node, int page_size, int nr)
225 {
226  clib_error_t *error = 0;
227  int n, needed;
228  error = clib_sysfs_get_free_hugepages (numa_node, page_size, &n);
229  if (error)
230  return error;
231  needed = nr - n;
232  if (needed <= 0)
233  return 0;
234 
235  error = clib_sysfs_get_nr_hugepages (numa_node, page_size, &n);
236  if (error)
237  return error;
238  clib_warning ("pre-allocating %u additional %uK hugepages on numa node %u",
239  needed, page_size, numa_node);
240  return clib_sysfs_set_nr_hugepages (numa_node, page_size, n + needed);
241 }
242 
243 
244 /*
245  * fd.io coding-style-patch-verification: ON
246  *
247  * Local Variables:
248  * eval: (c-set-style "gnu")
249  * End:
250  */
#define vec_validate(V, I)
Make sure vector is long enough for given index (no header, unspecified alignment) ...
Definition: vec.h:434
static clib_error_t * clib_sysfs_get_xxx_hugepages(char *type, int numa_node, int page_size, int *val)
Definition: sysfs.c:161
clib_error_t * clib_sysfs_get_surplus_hugepages(int numa_node, int page_size, int *v)
Definition: sysfs.c:218
u8 * format(u8 *s, const char *fmt,...)
Definition: format.c:419
u8 * va_format(u8 *s, const char *fmt, va_list *va)
Definition: format.c:387
clib_error_t * clib_sysfs_write(char *file_name, char *fmt,...)
Definition: sysfs.c:26
#define vec_reset_length(v)
Reset vector length to zero NULL-pointer tolerant.
#define clib_error_return(e, args...)
Definition: error.h:99
void unformat_init_string(unformat_input_t *input, char *string, int string_len)
Definition: unformat.c:1023
#define v
Definition: acl.c:495
struct _unformat_input_t unformat_input_t
#define clib_error_return_unix(e, args...)
Definition: error.h:102
clib_error_t * clib_sysfs_get_free_hugepages(int numa_node, int page_size, int *v)
Definition: sysfs.c:206
clib_error_t * clib_sysfs_read(char *file_name, char *fmt,...)
Definition: sysfs.c:50
void unformat_init_vector(unformat_input_t *input, u8 *vector_string)
Definition: unformat.c:1031
#define vec_free(V)
Free vector&#39;s memory (no header).
Definition: vec.h:336
clib_error_t * clib_sysfs_set_nr_hugepages(int numa_node, int page_size, int nr)
Definition: sysfs.c:117
#define clib_warning(format, args...)
Definition: error.h:59
clib_error_t * clib_sysfs_get_nr_hugepages(int numa_node, int page_size, int *v)
Definition: sysfs.c:212
u64 uword
Definition: types.h:112
#define vec_len(v)
Number of elements in vector (rvalue-only, NULL tolerant)
unsigned char u8
Definition: types.h:56
static void unformat_free(unformat_input_t *i)
Definition: format.h:161
#define clib_unix_warning(format, args...)
Definition: error.h:68
uword va_unformat(unformat_input_t *i, const char *fmt, va_list *args)
Definition: unformat.c:833
uword unformat(unformat_input_t *i, const char *fmt,...)
Definition: unformat.c:972
clib_error_t * clib_sysfs_prealloc_hugepages(int numa_node, int page_size, int nr)
Definition: sysfs.c:224
u8 * clib_sysfs_link_to_name(char *link)
Definition: sysfs.c:90